A former prime minister of Norway has spoken of his shock after he was held and questioned at Washington Dulles airport because of a visit to Iran three years ago.

Kjell Magne Bondevik, who served as prime minister of Norway from 1997-2000 and 2001-05, flew into the US from Europe on Tuesday afternoon to attend this week’s National Prayer Breakfast.

He was held for an hour after customs agents saw in his diplomatic passport that he had been to Iran in 2014. Bondevik said his passport also clearly indicated that he was the former PM of Norway.

“Of course I fully understand the fear of letting terrorists come into this country,” he told ABC7. “It should be enough when they found that I have a diplomatic passport, [that I’m a] former prime minister.

“That should be enough for them to understand that I don’t represent any problem or threat to this country and [to] let me go immediately, but they didn’t.”

Bondevik, who is the president of the Oslo Centre, a human rights organisation, said he was placed in a room with travellers from the Middle East and Africa who were also facing extra scrutiny.

He said he was ordered to wait for 40 minutes, before being questioned for another 20 minutes about his trip to Iran, which he had taken to speak at a human rights conference.

“I was surprised, and I was provoked,” he said. “What will the reputation of the US be if this happens not only to me, but also to other international leaders?”

An executive order signed by Donald Trump last week temporarily bans all travellers from seven Muslim-majority countries – Iran, Iraq, Libya, Yemen, Syria, Sudan and Somalia – from entering the US. It also suspends the US refugee resettlement programme for 120 days and puts an indefinite stop to the acceptance of Syrian refugees.

The order caused chaos at airports across the US and sparked protests and worldwide condemnation. Many people who were en route to the US when the order was hastily signed, including those with green cards, were detained on arrival at US airports, denied boarding on to US-bound flights, or taken off planes by security officials before takeoff.

Bondevik said Dulles officials told him he had been detained because of a 2015 law signed by Barack Obama that placed restrictions on travellers from those seven countries, or travellers from elsewhere who had recently visited those countries.

But he said he had never had a problem visiting the US before, and that his office was told by the US embassy in Oslo before his trip that his passport and a separate electronic travel authorisation were all he needed.

Speaking to the TV2 channel, Bondevik expressed further concern about the Trump administration’s tactics. “I understand the fear of terror, but one should not treat entire ethnic groups in such a way,” he said.

“I must admit that I fear the future. There has been a lot of progress over the last 10 years, but this gives great cause for concern, in line with the authoritarian leaders we see controlling other major countries.”

A spokesperson for US Customs and Border Protection said it was prohibited by law from discussing specifics of any individual’s admissibility review.

On Friday, Iran took retaliatory action by banning US wrestlers from participating in the Freestyle World Cup, one of the most prestigious competitions in international wrestling.

The IRNA news agency quoted Iran’s foreign ministry spokesman, Bahram Ghasemi, as saying a special committee reviewed the case and “eventually the visit by the US freestyle wrestling team was opposed”.

Ghasemi said the policy of the new US administration left Iran no other choice but to ban the wrestlers.